Wow, this thread blew up...looks like I need to do a little splitting up.(Just gotta figure out how!!! :redneck
wait, this **** is really interresting! who cares if they hijacked me? :corn:
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wait, this **** is really interresting! who cares if they hijacked me? :corn:
gave me a boner too! twice.... nothing like that sand cheby tho, sorry Tom Tom!:kiss:
leadfoot067
Well-Known Member
tomsbrokeagain
Well-Known Member
That sand cheby wont pull grants pass at 60 mph loaded down to 26k:fawkdancesmiley:
zukkev
Cornfuzzled yet again...
well, mount some paddles up on your dirty-max and we'll see if it makes me as warm and fuzzy as that big block did smashing around?:;
Dear joshwho?;
One. Last. Time. You are NOT producing 32 PSI of boost PRESSURE with ANY forced induction system! The engine cannot take that amount of PRESSURE.
Please take note of the key word : PRESSSURE. You are obviously confusing PRESSURE with WEIGHT! Maybe this explanation will help:
Difference between pounds of boost and PSI?
Whats the difference between "lbs of boost" and "PSI" when talking about blowers and turbos? Ive searched and searched and searched and cant find anything.
Any help is appreciated. Thanks.
* 4 years ago
* Report Abuse
Additional Details
I know what "lbs of boost" and "PSI" are.
Lbs = Volume
Psi = Pressure
If you fill a car tire with 5lbs of air, it may be at 10psi, but if you fill a bicycle tire with 5lbs of air, it may be at 50psi.
Am I correct in assuming that if one cars supercharger makes 5lbs of boost, he may be running at 10psi, but if the same supercharger were on a smaller car with a smaller engine and it made 5lbs of boost, it might be pushing 25psi?
The figures are just examples.
I took this explanation from here:
http://answers.yahoo.com/question/index?qid=20070526150412AAdCbrl
Next:
What is the difference between a turbocharger and a supercharger on a cars engine?
Let's start with the similarities. Both turbochargers and superchargers are called forced induction systems. They compress the air flowing into the engine* (see How Car Engines Work for a description of airflow in a normal engine). The advantage of compressing the air is that it lets the engine stuff more air into a cylinder. More air means that more fuel can be stuffed in, too, so you get more power from each explosion in each cylinder. A turbo/supercharged engine produces more power overall than the same engine without the charging.*
*The typical boost provided by either a turbocharger or a supercharger is 6 to 8 pounds per square inch (psi). Since normal atmospheric pressure is 14.7 psi at sea level, you can see that you are getting about 50-percent more air into the engine. Therefore, you would expect to get 50-percent more power. It's not perfectly efficient, though, so you might get a 30-percent to 40-percent improvement instead. *
*The key difference between a turbocharger and a supercharger is its power supply. Something has to supply the power to run the air compressor. In a supercharger, there is a belt that connects directly to the engine. It gets its power the same way that the water pump or alternator does. A turbocharger, on the other hand, gets its power from the exhaust stream. The exhaust runs through a turbine, which in turn spins the compressor (see How Gas Turbine Engines Work for details).
There are tradeoffs in both systems. In theory, a turbocharger is more efficient because it is using the "wasted" energy in the exhaust stream for its power source. On the other hand, a turbocharger causes some amount of back pressure in the exhaust system and tends to provide less boost until the engine is running at higher RPMs. Superchargers are easier to install but tend to be more expensive.
I took this explanation from here:
http://auto.howstuffworks.com/question122.htm
In short, if boost PRESSURE is increased to 32 PSI you've effectively DOUBLED the sea level PRESSURE of 14.7 PSI. Needless to say, that would mean that the engine is ingesting 300 PERCENT more air than previously, and needless to say, that cannot happen with a piston driven internal combustion engine.
The 32 POUNDS that you are reading on the boost gauge refers to the WEIGHT of the air that is entering the engine and NOT the PRESSURE which the air is being subjected to.
I seriously do not know what you and others cannot understand about this concept. If you were to connect a vac/boost gauge to your intake manifold, as soon as the exhaust gases were sufficient to spool up the turbo to it's rated output, you would find that the turbocharger is producing 3 to 6 POUNDS PER SQUARE INCH of boost PRESSURE, after which time the gauge would remain rock steady, as the waste gate would be regulating the turbo's maximum rated output. This would be NFG if you wanted to know the engine's work load status at any given time. The gauge would ONLY tell you that the turbo is functioning properly.
On the other hand, with the same gauge connected to the manifold of a Roots style blower, the vac/boost gauge would normally show the intake as being under a vacuum state. The only time that the gauge will show PRESSURE IN POUNDS PER SQUARE INCH would be if the engine were under a load, such as climbing a grade or if the throttle plates were close to the WOT position.
Therefore, turbos need a different style of gauge in order to accurately determine the engines work load status. This is accomplished by measuring the WEIGHT of the air which is passing through the turbocharger. The VOLUME of the air is determined in CUBIC FEET PER MINUTE and the WEIGHT of that VOLUME is expressed in POUNDS.
I do realize that the rice rocketing crowd tends to confuse POUNDS OF BOOST(which is a measurement of WEIGHT) with BOOST PRESSURE IN PSI(which is a measurement of applied force) however no one has ever accused any of those guys of being Albert Einstein either.:haha:
Your friend;
LAMAR
One. Last. Time. You are NOT producing 32 PSI of boost PRESSURE with ANY forced induction system! The engine cannot take that amount of PRESSURE.
Please take note of the key word : PRESSSURE. You are obviously confusing PRESSURE with WEIGHT! Maybe this explanation will help:
Difference between pounds of boost and PSI?
Whats the difference between "lbs of boost" and "PSI" when talking about blowers and turbos? Ive searched and searched and searched and cant find anything.
Any help is appreciated. Thanks.
* 4 years ago
* Report Abuse
Additional Details
I know what "lbs of boost" and "PSI" are.
Lbs = Volume
Psi = Pressure
If you fill a car tire with 5lbs of air, it may be at 10psi, but if you fill a bicycle tire with 5lbs of air, it may be at 50psi.
Am I correct in assuming that if one cars supercharger makes 5lbs of boost, he may be running at 10psi, but if the same supercharger were on a smaller car with a smaller engine and it made 5lbs of boost, it might be pushing 25psi?
The figures are just examples.
I took this explanation from here:
http://answers.yahoo.com/question/index?qid=20070526150412AAdCbrl
Next:
What is the difference between a turbocharger and a supercharger on a cars engine?
Let's start with the similarities. Both turbochargers and superchargers are called forced induction systems. They compress the air flowing into the engine* (see How Car Engines Work for a description of airflow in a normal engine). The advantage of compressing the air is that it lets the engine stuff more air into a cylinder. More air means that more fuel can be stuffed in, too, so you get more power from each explosion in each cylinder. A turbo/supercharged engine produces more power overall than the same engine without the charging.*
*The typical boost provided by either a turbocharger or a supercharger is 6 to 8 pounds per square inch (psi). Since normal atmospheric pressure is 14.7 psi at sea level, you can see that you are getting about 50-percent more air into the engine. Therefore, you would expect to get 50-percent more power. It's not perfectly efficient, though, so you might get a 30-percent to 40-percent improvement instead. *
*The key difference between a turbocharger and a supercharger is its power supply. Something has to supply the power to run the air compressor. In a supercharger, there is a belt that connects directly to the engine. It gets its power the same way that the water pump or alternator does. A turbocharger, on the other hand, gets its power from the exhaust stream. The exhaust runs through a turbine, which in turn spins the compressor (see How Gas Turbine Engines Work for details).
There are tradeoffs in both systems. In theory, a turbocharger is more efficient because it is using the "wasted" energy in the exhaust stream for its power source. On the other hand, a turbocharger causes some amount of back pressure in the exhaust system and tends to provide less boost until the engine is running at higher RPMs. Superchargers are easier to install but tend to be more expensive.
I took this explanation from here:
http://auto.howstuffworks.com/question122.htm
In short, if boost PRESSURE is increased to 32 PSI you've effectively DOUBLED the sea level PRESSURE of 14.7 PSI. Needless to say, that would mean that the engine is ingesting 300 PERCENT more air than previously, and needless to say, that cannot happen with a piston driven internal combustion engine.
The 32 POUNDS that you are reading on the boost gauge refers to the WEIGHT of the air that is entering the engine and NOT the PRESSURE which the air is being subjected to.
I seriously do not know what you and others cannot understand about this concept. If you were to connect a vac/boost gauge to your intake manifold, as soon as the exhaust gases were sufficient to spool up the turbo to it's rated output, you would find that the turbocharger is producing 3 to 6 POUNDS PER SQUARE INCH of boost PRESSURE, after which time the gauge would remain rock steady, as the waste gate would be regulating the turbo's maximum rated output. This would be NFG if you wanted to know the engine's work load status at any given time. The gauge would ONLY tell you that the turbo is functioning properly.
On the other hand, with the same gauge connected to the manifold of a Roots style blower, the vac/boost gauge would normally show the intake as being under a vacuum state. The only time that the gauge will show PRESSURE IN POUNDS PER SQUARE INCH would be if the engine were under a load, such as climbing a grade or if the throttle plates were close to the WOT position.
Therefore, turbos need a different style of gauge in order to accurately determine the engines work load status. This is accomplished by measuring the WEIGHT of the air which is passing through the turbocharger. The VOLUME of the air is determined in CUBIC FEET PER MINUTE and the WEIGHT of that VOLUME is expressed in POUNDS.
I do realize that the rice rocketing crowd tends to confuse POUNDS OF BOOST(which is a measurement of WEIGHT) with BOOST PRESSURE IN PSI(which is a measurement of applied force) however no one has ever accused any of those guys of being Albert Einstein either.:haha:
Your friend;
LAMAR
WHITE TRASH1
fruit stripe
Wow all that drivel and it's fawking wrong. NO ONE measures the weight of air when speaking of forced induction. 5 lbs. of air is a huge amount even compressed so that argument is ****ing worthless. People speak of psi, pounds of Pressure per Square Inch easy as that. Not volume that is controlled by the proper matching of components.
I run my shop compressor at 130 psi does that mean that if I unplug the motor and drain the tank of its compressed air that it'll weight 130 lbs less? No it doesn't. Get the **** out of here with your trolling.
I run my shop compressor at 130 psi does that mean that if I unplug the motor and drain the tank of its compressed air that it'll weight 130 lbs less? No it doesn't. Get the **** out of here with your trolling.
Dear WHITE TRASH;Wow all that drivel and it's fawking wrong. NO ONE measures the weight of air when speaking of forced induction. 5 lbs. of air is a huge amount even compressed so that argument is ****ing worthless. People speak of psi, pounds of Pressure per Square Inch easy as that. Not volume that is controlled by the proper matching of components.
I run my shop compressor at 130 psi does that mean that if I unplug the motor and drain the tank of its compressed air that it'll weight 130 lbs less? No it doesn't. Get the **** out of here with your trolling.
Hey dipshit, tell me how you can push 32 POUNDS OF PRESSURE through a 2.5" fawking inlet tube? Let's see if your shop's compressor can handle THAT type of requirement? :flipoff:Why YOU get the **** out of here with YOUR trolling?
Your friend;
LAMR
Binder
Well-Known Member
Lamar. Turbo boost is definitely in PSI. A boost gage has no provisions to measure volume. Yes increased volume is what we're trying to accomplish but there's no real good way to measure the volume directly. I'm not aware of any systems where a mass air flow gage is used to measure a turbos output are you? A 2.5" inlet tube can be thought of as just another vessel in which compressed air is stored or transferred. Remember volume isn't important when we're talking in terms of compressed air/fuel mixture and when the mixture would self ignite due to increased pressure and resulting temperature......
Binder
Well-Known Member
Here's a picture of a turbo boost gage just because. Boost-Press-PSI
WHITE TRASH1
fruit stripe
By your ignorant logic a child would not be able to hold a balloon filled with air as it would be too heavy. Think about it... Well on second thought don't, you'll just hurt yourself. :haha:
so I am stoked, I did in fact get a 4 bolt main block:awesomework:
just like all you guys said its a bitchen block cause it will be able to hold up to 1200 hp and @30 PSI boost, with minimal amounts of work, if i decide to go that way?:kiss:
:stirpot:
just like all you guys said its a bitchen block cause it will be able to hold up to 1200 hp and @30 PSI boost, with minimal amounts of work, if i decide to go that way?:kiss:
:stirpot:
ain'tstuckjustresting
RIP Mister 12/5/12
Yep, my boost gauge in my toolbox that I've used for years is an old acetylene gauge. Have I been diagnosing engines wrong for 10yrs because acetylene is lighter than air?
hpoop:
hpoop:Dear Binder;
Actually volume is VERY important when discussing an engine's performance.
I've also taken the liberty of asking a bud of mine (who now works for Garrett) why boost pressures in turbos seem to be so much higher than boost pressures for blowers. He informed me that the reason why is because the outlet of turbos are so much smaller. This makes sense to me.
He also went to explain that the high boost numbers are not truly indicative of performance. 32 PSI in a 2.5" outlet tube is about the same as 2-3 PSI in the manifold of a blower driven engine. It would seem that the intake volume requirements for a small engine are much lower than the requirement for a large engine, which is why using a turbo, or even twin turbos, on a high displacement engine are impractical.
So then I asked him the big question, which was "How much does a turbo increase performance?" He went on to tell me that while a turbo can possibly increase a small engine's performance by 65%, again it's a misleading number when dealing with smaller displacement engines, because an engine which is producing 210 HP from the factory will only see an overall HP gain of around 135 HP.
I then asked why not use a belt driven supercharger or a small blower instead of a turbo and he explained that the losses from the supercharger's parasitic drag would be too great for a small engine to be able to cope with, therefore turbos are used. With a 502 CID engine, a 10% power loss due to parasitic blower drag is quite acceptable because of the large amount of power that's on tap to begin with, therefore a 10% power loss is basically unnoticeable.
We then discussed building engines for maximum power output and the end result was the same as I've been preaching all along. Any engine's max output ceiling is not determined by blowers, turbos, cylinder head designs, flow characteristics, ignition systems, etc. The determining factor of a engine's maximum power potential is regulated by the octane rating of the fuel.
All of the trick components in the world will not allow us to work around the inescapable conclusion that the maximum compression ratio of today's modern engines is 12.4:1 before detonation occurs. Therefore, unless exotic, and very costly, fuels or fuel additives such as various octane boosters or nitrous oxide are used, the cap of performance is determined by the octane rating of the fuel being used.
Your friend;
LAMAR
WHITE TRASH1
fruit stripe
Wrong. Face it you're wrong and the fact that you keep using hard equations proves that you don't have a ****ing clue. Keep trying though because it is funny to see you make **** up and site your "expert friends" in the industry. :haha:
Binder
Well-Known Member
But we or at least I'm not discussing an engines performance. I'm discussing the threshold of when a fuel, pump gasoline preignites which isn't relative to a volume it's relative to heat obtained by a pressure.:;
Binder
Well-Known Member
Go fawk yourself.:fawkdancesmiley:
Dear Binder;
Yes, when air is compressed it produces friction which is where the heat comes from. High octane fuels permit higher compression ratios in two ways. First, because they will not pre-ignite under a high compression load and second, because the higher octane fuel inside of the fuel/air charge effectively chills the cylinder more efficiently than lower octane fuels do.
That's why air-cooled radial engines are able to sustain much higher compression ratios. Attempting to run a radial engine on today's 100LL aviation fuel is usually disastrous because the engine's cylinders tend to overheat so rapidly. Radials like the taste of 115/145 Avgas and they tend to get cranky when fed anything else.
Your friend;
LAMAR
